Put the butter in a pot and cook for 1 minute until very hot. Add the fennel seeds and ginger, cover and cook for 45 seconds. Add the parsnip and 1—2 tbsp water.
Cover and cook for 8 minutes, turning once, until the parsnip is really tender.
Add the boiling chicken stock (broth) and cook for 3 minutes. Remove the ginger and puree the soup in a blender or food processor.
Add enough hot milk to reach the desired consistency, season to taste with salt and pepper and stir in a pinch of garam masala.
Heat through in the microwave for a couple of minutes if necessary and serve.